How do I search through my log files for errors? (Linux)

You can use several options to streamline the viewing of large text files, such as /var/log/messages. Some of these options are described in the article below.

# head
The head command will print the first 10 lines of a file to the screen. This can be coupled with the options “-n ” to display a larger number of lines. So for instance,
# head -n 40
would display the top 40 lines of a text file.

# tail
Much like #head, the tail command will display the last 10 lines of a text file. This can also be coupled with the option “-n ” to display a larger number of lines.

# cat
Cat will print the entire contents of a file to the screen.

You can also add a ‘| grep’ to the end of any of these commands to search for a specific word. For instance,

# cat testing.txt | grep error

would only report the lines containing the word ‘error’. Note that this is case-sensitive.